EXTENDED-SPECTRUM BETA-LACTAMASE-PRODUCING GRAM-NEGATIVE BACTERIA ISOLATED FROM OCULAR INFECTIONS: PREVALENCE AND PATTERNS OF ANTIBACTERIAL RESISTANCE

Abstract

Pseudomonas aeruginosais a gram-negative rod-shaped bacterium occurs in soil, water, sinks, and medical equipment. It causes 559,000 deaths all over the world each year. The emergence of extended-spectrum beta-lactamases (ESBLs) further limits beta-lactam treatment options due to increased antibiotic resistance. In this study, we looked at the main genes associated with ESBL from clinical isolates at District Hospital Karak in Khyber Pakhtunkhwa, Pakistan, as well as the frequency of isolates that produce Pseudomonas aeruginosa(ESBL). A cross-sectional hospital-based investigation was performed from January to November 2017. Overall, 748 clinical specimens were collected. P. aeruginosa was identified by standard culture and biochemical methods; ESBL production genes were confirmed by PCR and agarose gel electrophoresis. Out of 748 clinical specimens, 400 (53.5%) were confirmed as Pseudomonas aeruginosa. Among these, 80 isolates(20.0%) were ESBL producers, while 320 (80.0%)were non-ESBL producers. ESBL-positive isolates were mainly recovered from the OPD (34/80; 42.5%), followed by the OT (23/80; 28.75%), ICU (21/80; 26.25%), and gynecology ward (2/80; 2.5%). Age-wise, the highest frequency was observed in patients aged 36–50 years, followed by 26–35 years. We noticed that the Females contributed 56/80 (70.0%) ESBL-positive isolates and males 24/80 (30.0%), although the ESBL positivity rate was equal in both genders. Specimen-wise, pus samples (30/80; 37.5%) were the major source, followed by urine samples (20/80; 25.0%), while tracheal swabs showed the highest ESBL positivity rate (38.88%). Molecular analysis showed OXA as the predominant gene (37/80; 46.25%), followed by CTX-M (29/80; 36.25%) and TEM (14/80; 17.5%). Dual gene carriage was found in 15 isolates (18.75%), mainly OXA + TEM (8/80; 10.0%), followed by OXA + CTX-M (5/80; 6.25%) and CTX-M + TEM(2/80; 2.5%). This study confirms a significant burden of ESBL-producing P. aeruginosa, mainly driven by OXA genes, highlighting the need for routine surveillance, stewardship, and infection control.